Bronwyn Tarr, an Oxford researcher who was in Leiden recently, claims that dancing improves social bonding.

“People all over the world play music, sing and dance. Many people don’t think it’s remarkable, but it is. Someone must have made the first musical instrument, someone must have sung the very first song; we think it happened a hundred thousand years ago or more.

“Something that is so widespread must have a purpose. Evolutionary psychology offers a number of reasons for it: dancing can be important when choosing a partner. It can have a part in defence – look at the Haka of the Maoris. Our group is concentrating on the idea that dancing is important for social cohesion.

“If you and I synchronize– even something simple like clicking our fingers – you will like me better and suppose I’m more like you. That’s easy for two to do, but it’s more difficult in a large group. It’s harder to see everyone and process all the information. Music gives us a framework; it makes it easier for everyone to move in sync.

“Social animals have relatively large brains, particularly a large neocortex, the part we use for social and emotional processes. It looks as if animals that live in larger groups also have a larger neocortex, especially in groups with more complex relationships. In the case of social insects, all the animals are related and the naked mole-rats that I studied earlier are so inbred that the same applies to them. Defending your family and your partners is logical, in evolutionary terms, but many social animals also have relationships that do not involve family ties or sex: friendships.

“However, it takes time to make friends. Chimpanzees can spend many hours of the day grooming each other. It’s not just about getting rid of parasites: they enjoy it. Their brains produce endorphins, “pleasure chemicals” so they long to do it again. They also feel better if they groom with that particular chimp. However, we live in much larger groups than apes do, so we can’t rely on grooming. That’s why we use other mechanisms to make and reinforce our friendships: language, religion and music.

“Our group at Oxford is studying the exact part dancing plays in bonding. How exactly does it connect people? How important is the music? It’s quite hard to study, because people synchronise with each other very quickly – even babies. If you want to examine synchronisation, you have to prevent people from synchronising. You can tell them to dance out of sync, but it’s very difficult.

“We decided to play a silent disco and people listened to different songs on their headphones to ensure they didn’t move to the same beat. We also worked with researchers in Barcelona on experiments in a virtual reality. Before we start, we tell people we’re measuring the effects of light. The participants go into the virtual room one by one and are asked to dance with someone. The other people in the room aren’t real people: they’re operated by the researchers, but the test subjects don’t know. All the avatars are the same to avoid disturbances because of things like one dancing partner being more attractive than another.

“The other avatars dance either in time with you or with a delay. You like the avatars who dance in sync with you better: it doesn’t even matter whether you believe that the other person is human: our brains are very eager to be tricked in this way. “If you dance, you are bonding. We also discovered that your pain threshold rises: test subjects who danced in sync are less likely to say that an inflated blood pressure monitor hurts.

“We don’t research this because we want to alleviate pain, but because the pain threshold is a proxy for the endorphin system that affects chimps when they make friends. Does it work like that with us, or are we talking about two parallel processes? We’re still not sure, but in all events we can see both psychological and physical effects.

“Many people say they’re not musical and they can’t dance. That’s just not true. Everyone can follow a beat. Dancing is part of what makes us human: we humans have a love affair with music. It brings us together, and I think that’s a heartening story: we’re not just separate individuals, we’re a group. We should indulge in that feeling, and dance more.”